31 December 2008

In an essay in the 20 December 2008 issue of the New Scientist, Michael Brooks suggests to give the public “more say in what science gets funded” instead of letting the process be "driven by scientists’ demands for ever more specialised efforts.” The former option is supposed to get the public more involved in science and prevent the “disappearance of science from culture".

The public has no control over how any branch of the government spends their tax dollars, so why should they have any say in what scientists want to do with it? Why single out science funding for public influence? Hey, why not give us some control over how the military spends our tax money? Is the government willing to give the public more say in how it spends their monies in all and every project it undertakes? If no, leave the control of science funding to scientists. And leave the politicians out of it too.

Brooks writes:

But that suggests people are not qualified to judge how their money should be spent. How is that different from another unthinkable: a barrister arguing that a jury cannot appreciate the subtlety of a criminal case, so the verdict should instead be brought by a carefully selected handful of the barrister's peers?

That is a stupid analogy. A jury is supposed to consist of a defendant’s "peers", presumably meaning that they are not different significantly than the defendant in those shared characteristic that may influence their judgment of him or her. An ordinary layperson with no scientific background, on the other hand, cannot be expected to pass sound judgement on a trained scientist’s scientific ideas. I don’t mean to humiliate a layperson, but this is only a matter of expertise and education. I don’t advise NASA on how to build spaceships; I don’t tell highway engineers how to build highways; I don’t even attempt to teach garbage men how to pick up garbage; because I don’t know how to do any of those things. In return, I don’t want people who think slugs are snails that have come out of their shells* telling me how to spend their tax money (not that I get any government funding).

Scientists have their own peer review system administered by other scientists. Let them be their own overseers and leave the public out of it.

*Yes, I did once meet a layperson who sincerely thought that slugs were snails that had temporarily left their shells.

30 December 2008

This marvelous drawing by my malacologist-artist (or, artist-malacologist) friend Marla Coppolino came a couple of days ago with her holiday wishes. You may see more of Marla's nature-inspired artwork here and here.

Marla explained her drawing as follows:

This Mesodon zaletus snail gets a special glimpse of a snowy world, without freezing its foot. In cold conditions, land snails crawl under the leaf litter and soil and withdraw tightly inside their shells to hibernate for the winter. Special compounds in the snails’ tissues prevent them from freezing. When the ground warms in the spring, the snails awaken and emerge.

She also noted that "no snails were harmed during the production" of her drawing.

Salicylic acid is a plant metabolite present in many plants, including rice, barley and soybean. Its functions in plants range from heat production to disease resistance (Raskin, 1992). In humans, it has fever and pain reducing effects. It is also the synthetic precursor of the drug aspirin, acetylsalicylic acid.

In this paper, Paterson et al. present several intriguing pieces of evidence on the presence of salicylic acid in the blood of various animals and humans. Among the more than 30 animals they tested, 2 birds, the burrowing owl and the Nene had the highest blood concentrations of salicylic acid (9.9 and 5.6 μmol/L, respectively). They were followed by both herbivorous and carnivorous species, including the Asian elephant (1.6 μmol/L), the Burmese python (1.4 μmol/L ) and the tiger (0.67 μmol/L). The only animals that had levels of salicylic acid below the limit of detection of the method used were 2 crustacean species that were also the only invertebrates in the list.

Likewise, vegetarian and nonvegetarian humans who had not recently consumed aspirin had overlapping ranges of blood salicylic acid levels and comparable median values of 0.11 and 0.07 μmol/L, respectively. In comparison, the median level of salicylic acid in the blood of aspirin users was 10 μmol/L. In addition, salicylic acid was found in the blood of 6 patients who had been fasting prior to abdominal surgical procedures.

Interestingly, in 2 groups of germ-free mice and rats serum salicylic acid levels were higher than those in control groups.

The authors conclude that humans not only obtain some salicylic acid from the foods they consume but that they also appear to synthesize it endogenously. One speculation presented in the paper is that salicylic acid, similar to its functions in plants, may also have defensive and regulatory roles in animals.

28 December 2008

Today's rainy and unseasonably warm* weather brought the native slugs in the nearby woods out of their winter hiding places. After scanning several beech trunks, I saw 2 Megapallifera mutabilis on their way down from the tree tops. Here is one of them.

I brought both slugs home and placed them into a makeshift slugarium, a large glass container containing dead tree leaves and several pieces of beech bark. A glass plate (from a picture frame) is serving as the lid. I will be putting a small vial of water inside the container to keep the humidity high, otherwise the slugs will die.

This is going to be the slugs' home for several weeks during which they will be observed, photographed, examined, maybe poked occasionally and probably subjected to some mild experiments, all in the name of science, of course. As I mentioned in this post, Megan and I collecting data for a presentation at next summer's AMS meeting in Ithaca, New York. These slugs will have the honor of being part of our project. I don't intend to kill them and will return them to where they came from eventually.

I will continue to write about them as things start to happen.

Here is the same slug photographed above now resting on a beech bark inside the slugarium.

In this post I wrote about a snail and a slug that were helping themselves some dog feces. Now it turns out that terrestrial gastropods may have been into coprophagy for quite a long time, at least since dinosaurs were around.

In a very interesting paper, Chin et al. report the discovery of approximately 77 million-year old dinosaur coprolites (fossilized dung) containing snail shells. These came from the Two Medicine Formation in northwestern Montana. More than 130 snail shells, intact or fragmented, were observed on or in 6 of the 15 coprolites at the location. The shell remains represented at least 7 fossil taxa of 4 terrestrial and 3 aquatic snails.

A piece of dinosaur coprolite (top) and a snail shell sticking out of one (bottom). From Fig. 2 in Chin et al.

As I discussed in my aforementioned post, land snails and slugs do eat feces, but the presence of snail shells in coprolites does not necessarily mean that the snails were feeding on the feces. The authors consider 2 possible scenarios to explain their findings: 1. the dinosaurs ate the snails; 2. the snails were eating the dinosaurs’ feces. To these I will add a 3rd possibility that Chin et al. mention only in passing: 3. the mixing of the snails and the dinosaur dung happened during the flooding event that apparently buried the dung.

The subject dinosaurs (tentatively identified as members of Maiasaura) certainly had a peculiar diet: their coprolites were composed mostly of "fragmented conifer wood". They may have been feeding on fungi growing on rotting wood and also ingesting some wood along with any snails that may have been present on the wood or the fungi. I am no expert on coprolites and so wouldn’t know if fungal remains in them could be identified. The authors, however, reject the possibility that the shells in the coprolites are the remains of ingested snails based on their contention that snail shells present in the dinosaurs’ food would likely have been crushed during chewing and the subsequent digestion. But I don’t think we can yet rule out that scenario. If the snails survived mastication more or less intact (only 30% of the coprolite shells were determined to be whole), they could also have survived digestion with minimal shell damage. For example, there is one report of freshwater mollusks surviving their fish predators’ digestive processes (Brown, 2007).

Chin et al. favor the 2nd scenario that the snails were eating the dinosaurs’ feces before they got fossilized along with their food. The problem I have with that explanation is the presence of both terrestrial and freshwater snails in the coprolites. The authors' explanation that first, the land snails were on the dung, then the area got flooded (implying that the land snails stayed on the dung underwater), and the freshwater snails came to feed on the dung and finally they all got fossilized seems a bit stretched.

I am leaning towards the 3rd explanation that all of the snails were deposited on the dinosaur feces as empty shells during a flooding event and got fossilized subsequently. Ancient coprophagous snails is, of course, a more intriguing interpretation and I hope more unburied feces will be found to clinch the case.

25 December 2008

24 December 2008

I finally finished reading last nite a book that was given to me as a present by my late aunt 43 years ago. Back in 1965, I had already read and enjoyed the Turkish translations of some of the more popular books of Jules Verne, including Five Weeks in a Balloon and Twenty Thousand Leagues Under the Sea. But The Kip Brothers, or Kip Kardeşler, either didn't sound as exciting as the others or was more difficult for me to follow at that young age. So the 2 unread volumes just sat on bookcases for all these years slowly crumbling and yellowing. Amazingly, they were not thrown out, given away or lost.

When I found them on a bookshelf in Mom's condo in Turkey back in October, I decided the time had come to read Kip Kardeşler. So I took the books with me.

I am sorry to say it was a tedious read. Verne's style was boring; he was repetitious and took too long to get to the point. Besides, there were long discourses on the geography and history of the southeast Pacific, international politics and the Fenians, while the Kip Brothers didn't even enter the story until chapter 7. On top of everything else, the translation was bad.

The story started out as a maritime adventure, then turned into a murder "mystery", although the identities of the murderers were revealed as they were committing it. The Kip Brothers got wrongly accused of the crime and spent a long time (the final third of the book) to clear their name. Verne's weakness was that he told too much to his readers and left very little to the imagination. He explained everything in detail even when what he was explaining was obvious. In this case, he would have crafted a much better story if he had hidden the identities of the murderers from his readers.

The climax of The Kip Brothers was a real letdown. I had been disappointed with Verne's science once before, but his resorting at the end of this book to the ridiculous late 19th century claim that a dead person's eyes retained an image of the last thing he saw took almost all the joy out of finishing it.

Incidentally, the Turkish translation of The Kip Brothers published in 1964 predates by 44 years the 1st English translation that came out in 2007 (available at Amazon).

23 December 2008

Bryant Walker (1856-1936), a lawyer by training, was an authority on terrestrial and freshwater mollusks of North America in the early 20th century. Yesterday, while skimming thru his list of publications detailed by Goodrich in this 1939 paper, I noticed that Walker’s first paper on mollusks titled "List of Land and Fresh-Water Shells found within a Circuit of Four Miles about Ann Arbor, Mich." and coauthored with Charles E. Beecher (1856-1904), had been published in 1876 in the Proceedings of Ann Arbor Scientific Association.

Several searches on the Internet for more information about the Ann Arbor Scientific Association was fruitless until I realized that Goodrich himself had provided more details about it and the paper by Walker & Beecher in this publication from 1943.

It turned out that the Ann Arbor Scientific Association had a very short, but busy and tumultuous lifespan of about a year. Goodrich wrote:

In that first and only year of the organization were lectures on geology, zoology, archeology, chemistry, botany, and meteorology. Probably the most ambitious paper of all was one on the flora in and about Ann Arbor, wherein 848 species of plants were recited. Walker and Beecher joined the society at the same time, in June, 1875...

The "Proceedings" of the Association that had the Walker & Beecher paper was nothing more than an appendix to its Constitution and By-Laws. But what became of the Ann Arbor Scientific Association? Goodrich continued:

Naturally, the short career of the association is a matter to wonder about. It has to be admitted that in America societies of the kind are commonly of few years and full of trouble, and that a certain inanition, if nothing worse, quickly comes upon them. Then, too, the Ann Arbor association came into being in the midst of the depression that followed the "panic of '73" and might be expected, as a result, to suffer difficulties with membership dues and printing bills.

But apparently there was another circumstance behind the early demise of the Association:

Dr. [Silas H.] Douglas was an active charter member. Professor [P. B.] Rose was secretary. These two entered upon a controversy which developed aspects of a mountain feud. If, as it is written, the University underwent earthquake-like reactions to the quarrel and the town became filled with highly vocal partisans, it can hardly be thought strange that a germinating scientific society, containing two resolute men at odds with each other, could not sustain the breath of life.

Goodrich didn't explain what the 2 men were quarreling about.

Walker, a junior at the University of Michigan at that time, survived the "earthquake" and had a long career in law and a successful avocation in malacology with 155 publications, while his coauthor Beecher went on to become professor of geology at Yale University until his untimely death in 1904.

Hopefully, some of the other long-running malacological publications, including the Journal of Conchology, the Proceedings of the Malacological Society, etc., will follow suit and make their old issues open access.

21 December 2008

In several groups of pulmonate snails and slugs there is a mucus gland located inside a depression near the tip of the tail. This gland is known as the caudal gland and the depression containing it as the caudal pit (or caudal fossa). The picture below shows the caudal pit of the slug Arion subfuscus. The swelling anterior to the pit and partially covering it is called the caudal horn.

The caudal pit (arrow) near the tip of the tail of a preserved specimen of Arion subfuscus. The ruler, as always, is in millimeters.

The caudal gland produces mucus that is thicker than that of the pedal gland underneath the sole. The mucus from the latter is what the slugs and snails crawl on. What is the function of the mucus from the caudal gland?

Drawing from Barr, 1927.

Barr (1927) thought that the mucus of the caudal gland was probably used to secure the slug to the surface it was on when it was descending from a tree or a wall. She also observed slugs eat the mucus from each other's caudal gland prior to mating. That observation indicated that the caudal mucus also had a function in mating.

Many years later, Richter (1980) observed the slug Ariolimax columbianus using a strand of caudal mucus to lower itself from trees and shrubs. In addition, he did some tests that demonstrated that the sticky caudal mucus was an effective deterrent against some slug predators, such as shrews and ground beetles.

19 December 2008

Over at Myrmecos Blog, Alex Wild has a set of his best insect pictures of 2008. I thought that was a great idea. So, I went thru the hundreds and hundreds of snail and slug photographs I have taken this year and selected what I think are the best 10, although there were several more equally good ones.

Most of my selections have already been on this blog. Here they are not in any particular order.

Eobania vermiculata crawling up a plant stem. This species was the subject of this post.

Gastrocopta contracta with its always dirty shell. This 2.4 mm-long snail was featured in this post. This picture was actually taken on 31 December 2007. I had to relax the "rules" for one day to include it in this batch.

Zebrina detrita crawling on dew covered grass. Photographed last October near Kastamonu, Turkey. The picture was used in this post.

Pomatiopsis lapidaria underwater This is one of those species that can't decide whether to be an aquatic or a terrestrial snail. It was the subject of this post. I put this snail in water to observe its behavior. It went to the edge of the container and immediately started crawling up. Obviously, it wasn't too happy about being in water. This picture shows it as it was attempting to get a hold of the side wall of the container.

Cochlicopa lubrica deep inside its shell As you can see, the snail can withdraw its body more than a whorl away from the aperture.

Chondrus zebra making a sharp turn Another species from Turkey. The significance of this picture is that it shows how short the snail's foot is compared to its shell.

Arion subfuscus eating a mushrooom. This slug, originally from Europe, is a naturalized denizen of North America. The large circular hole is the slug's pneumostome, the breathing hole that leads into its lung. I used this picture previously in this post.

A pair of Oxyloma retusa mating These snails were the subjects of this post.

Oxyloma retusa laying eggs Yes, they are among my favorite snails. More info in this post.

Last but not least, a Triodopsis struggling to free itself from the caliper jaws I thought this picture was a fitting tribute to my favorite leisure time activity: measuring snail shells.

18 December 2008

On my train ride back home yesterday, I read a short paper on collecting slugs by our colleagues Klee & Scheppat. In the very first paragraph they give a brief explanation of where to look for slugs and include this sentence (italics mine):

In these areas you can be successful in little valleys facing to the north with creeks up to rocky fields (even above the timberline), where the evening dewondenses.

Dewondenses? I seriously thought that may have been a word that hadn’t yet entered my vocabulary. However, a subsequent search in the dictionary failed to come up with anything even remotely similar. A Google search did find dewonden in some Dutch sentences. Taking into account the authors’ nationality, I even checked the German dictionary, but to no avail.

Finally, the obvious truth revealed itself. The original sentence must have been:

17 December 2008

God Testudo in front of McKeldin Library at the University of Maryland had received fresh offerings from its humble worshipers earlier today. May it deliver. Amen.

Don’t take anyone seriously who claims to believe in only one god. Deep inside, humans have remained and will forever remain polytheistic. I wouldn’t be surprised if in the (near) future the majority abandoned the current ostensibly monotheistic religions (and their gods, sons, prophets, saints, icons, holy men, demons, angels and the like) and returned to officially polyhteistic religions.

16 December 2008

Back in the summer of 2004 we did a week-long land snail survey of a national park in western Turkey. We followed an intense schedule, which we referred to as the snail bootcamp: we would get up early in the morning, eat breakfast, drive to the park, collect until sunset, drive back home, eat dinner, work on the day’s collections, go to bed. The next day it would be the same schedule over again. I don't know about the other guys, but I was having fun. We did take 2 breaks lasting 3 days, but only to collect elsewhere.

One of those side trips resulted in the discovery of a new clausiliid species, Idyla aydinensis, that was the subject of this post. A survey we did in Istanbul that summer that also resulted in a publication and was the subject of this post. But the results of the survey of the national park, the main activity of that season, still haven’t seen the day light. And the reason for that is that yours truly, who has about 90% of the specimens in his possession, has been dragging his feet.

My tasks are easier said than done: sort thru the bags and bags of shells, check the identifications we did in Turkey, identify what hasn’t been identified, take measurements and photographs when necessary, get the lots ready for deposition into museums, prepare a species list and write the manuscript. But the wholly justified complaints and reminders of my co-workers finally reached a point where I decided I couldn’t procrastinate anymore. I actually enjoy doing every one of my tasks, it’s just that...

So, a couple of weeks ago I set up in the basement a table dedicated to the specimens of the said survey.

There are still many bags that we didn’t have time to sort thru during our evening sessions while in Turkey. I really get a kick out of pouring the contents of such a bag into a tray and casting my eyes on them for the first time. Ooh, I wonder what’s in this one? It’s like opening a present.

These were from our station D24.

You can see 2 clausiliids, Albinaria puella and Bulgarica denticulata, Cantareus aspersus, Metafruticicola redtenbacheri and the flat Lindholmiola lens. The plastic tube is holding the micro shells.

Two of the most interesting specimens from this station were not even complete shells.

These two Cantareus aspersus shells were predated by an unknown predator that peeled the shells spirally to get to the snails. I suspect some rodent was the culprit. The larger shell on the right was probably an adult.

More to come about the interesting stuff from this survey as I make progress.

15 December 2008

The world's longest animal may or may not be the nemertean worm Lineus longissimus (ribbon worms; phylum Nemertea), which may or may not have been named after Carl Linnaeus (Carl von Linné). Gittenberger & Schipper (2008), discussing these matters in their short paper, indicate that, although the maximum length of 60 m for this worm cited in the literature may not be accurate, animals reaching lengths of up to 30 m have been seen (and they are only about 10 mm in width). They also note that the question of whether or not the genus Lineus was named after Linnaeus cannot be answered with certainty. The British botanist James Sowerby, who erected the genus in 1806 on the 99th anniversary of Linnaeus's birth, did not explain the etymology of Lineus. Moreover, if the genus had been named after Linné, the correct name would have been Linneus. (What was a botanist doing describing a worm genus, anyway?)

14 December 2008

If you and your 2-winged companions have had enough wine for one evening, what do you do with the rest of the bottle? I cork mine and put it in the refrigerator. As far as I am concerned, it'll still be drinkable for 2 more evenings.

In the The A.V. Club section of the print edition of last week's the Onion, some food experts offer their ideas on what to do with leftover wine. But for starters, the restaurateur Curtis Alfred asks "if the wine's that good, why was it left over anyway?" Likewise, the professional wine instructor Philip Prifold notes that "...most wines are typically dead within several hours after opening them." Right, but, the idea is to enjoy it without getting drunk, you know.

Apparently, saving the leftover wine for drinking it later is anathema to these people. However, various recipes are offered for turning the wine into something else for future use. Mr. Prifold makes vinegar out of his leftover wines. A couple of formulae are also offered to create miserable-sounding concoctions laden with "pumpkin pie spices, cloves, anise, cinnamon" and you name it.

12 December 2008

The British malacologist Arthur Edwin Boycott's (1877–1938) name is probably familiar to most current workers in the field. Some of his papers are still cited frequently. In Boycott's obituary published in the Journal of Conchology, Charles Oldham relays a funny story that characterizes the opinion most laypeople may have of grown-up naturalists rummaging around on their hands and knees in the field.

One day Boycott and a friend of his were collecting snails behind a wall along some rural road. They stood up as a car happened to be passing by.

The motorist, not without reason, suspected a trap, jumped from the car, threw up his hands and exclaimed, "What’s the matter; is anything wrong?" A puzzled look and the reply, "No, I am only looking for snails," exceeded his worst suspicions. Thinking that not only was he ambushed but ambushed by two lunatics he shouted, "Good God!", dashed for the car and, regardless of the risk he ran, drove off at full speed.

That this wasn't an isolated incident is demonstrated by the well known U.S. collector Leslie Hubricht's (1908-2005) complaints of his treatment by townsfolk during his countless collection forays. Hubricht wrote this in the April 1953 (vol. 66) issue of the Nautilus at a time when such comments could be inserted easily into manuscripts published in respectable journals.

I should warn the reader of the dangers of collecting in towns. There is a surprisingly large number of people who, instead of satisfying their curiosity by coming to me and asking what I am doing, will call the police. For the most part the police have been pleasant. But there was the time at Courtland, Virginia, when someone told the constable that there was a crazy man loose in the town. The constable rounded up a posse of about ten men before approaching me, in the event I should become violent. At Kinston, North Carolina, a man called the police, and then argued with them for at least fifteen minutes that I was a dangerous character to be securely locked up. He seemed to believe that the pose of snail collector was the favorite disguise of foreign spies. After the police left, he followed me around and carefully jotted down my license number as I drove out of town.

I've had my share of encounters with suspicious folks during my collection trips, but I will save those stories to future posts.

11 December 2008

Last Monday I visited Megan's lab at the University of Maryland. It had been more than 2 years since my previous visit. Megan's Ph.D. research is about slugs. So she's got quite a number of them around.

The smaller containers were for the smaller slugs, including these Pallifera sp., which grow to about 2 cm.

There were also several bigger containers for the...

bigger slugs like these Philomycus carolinianus. When fully stretched they can be 7-8 cm long.

Afterwards we went to a local eatery and had burritos for lunch. Our lunch conversation was, of course, about slugs and snails. We have been independently collecting data about some local slug species. So we decided to unite our efforts and have a joint presentation at next year's American Malacological Society meeting. We still have to do some experiments in the spring to try to duplicate in the lab what we've been observing in the wild. It'll be a fun project.

10 December 2008

Göbekli Tepe, a mound in southeastern Turkey supposedly representing the "world's first temple", has become a major Neolithic site featuring stone pillars with intricate carvings of various animals. A mostly informative article by Sandra Scham in the November/December 2008 issue of Archaeology is about the recent findings in Göbekli Tepe.

Near the end of her piece, Scham translates the Turkish name of the place as "hill of the navel". Wrong.

Yes, one meaning of göbek is indeed "navel", and another is "belly". But göbekli means "pot-bellied". For example, see the translation given by From Language to Language and also the on-line dictionary of the Turkish Language Society.

Therefore, Göbekli Tepe means "pot-bellied hill". The name probably refers to the shape of the mound.

I suppose Scham doesn't know Turkish and so I can't be too critical of a little translation mistake. Alas, she didn't stop there, but, instead, continued into the realm of silliness:

...to me the site is reminiscent of other places known as sacred "navels" of the earth, such as Cusco in Peru and Delphi in Greece. Many religions use the metaphor of a human birth to describe the creation of the world, and the site where the cosmos began is equated with the place where the umbilicus was attached.

Blah, blah, blah. As far as Göbekli Tepe is concerned, this is nonsense of cosmic proportions. Does Scham really think that the symbolic association of the place with a navel—assuming that the neolithic hunter-gatherers indeed considered that association—survived for 10,000 years, even though the structures at the site had become completely buried prior to the recent excavations, and was somehow re-expressed in the present-day Turkish name of the hill?

Translations from unfamiliar languages could be tricky with unwanted results. Here is a recent hilarious example.

09 December 2008

A week ago we developed a fruit fly infestation in the house. The event that triggered the explosion in the population of our close domestic associates was some kiwis and grapes that were being kept on a countertop. We have since gotten rid of the fruit, but Drosophila are still hanging around. The cold weather we've been having may also be forcing them to stay indoors.

Last night, my glass of Cabernet Sauvignon was their focus of attention.

A bunch of them quickly developed an intimate relationship with the fermented grape juice. So much so that eventually one lost its footing and ended up in on the wine; they are not heavy enough to overcome the surface tension and just float like water striders, but quite helplessly, unlike the latter.

I rescued it and put it back on the rim of the glass. It fell right back in. It had definitely had one whiff too much.

There are many animal species whose habitats are restricted to coastal areas. Some of the snails in that group have been the subjects of several posts on this blog (for example, here, here and here). Why can’t such species survive away from the sea, their ancestral home?

Some species of terrestrial talitrid amphipods (Talitridae), also known as landhoppers, likewise live only in the coastal zone. In this paper, Richardson et al., (pdf) tried to shed some light on the factors that may be limiting the landward migrations of certain Tasmanian landhoppers. They note that there are 2 main hypotheses to explain the restricted ranges of coastal landhoppers, which, obviously, apply to all other strictly coastal animals:

1. Coastal species are limited by a physiological requirement for salt, which is present, for obvious reasons, in high enough concentrations only in coastal soils.

2. Coastal species may not need high salt levels in their habitats and have a superior tolerance of elevated salt concentrations nevertheless, but are excluded from inland habitats by competition or some other biological interaction.

To test these hypotheses, the authors did a relatively simple experiment. They collected batches of litter containing the landhopper Austrotroides maritimus, whose distribution, as its name implies, is confined to a zone less than 100 m from the high-water mark. These they transplanted into enclosures 30 m inland from the most inland record of the species. For a period of 5 months, they applied at monthly intervals to each enclosure either dry sea salt, salty water, fresh water or nothing. Initially, each enclosure contained approximately the same number of landhoppers. At monthly intervals, they also estimated the number of landhoppers in each enclosure and compared these with the numbers obtained from untreated enclosures within the natural coastal range of A. maritimus.

Here are the main results of the study.

The top curve shows the population increase within the natural coastal range of the landhoppers. This was probably an expected seasonal phenomenon, since the experiment was done during the summer months. Among the experimental enclosures away from the coast, only in those that received dry salt was there an initial increase in landhopper numbers prior to a sharp decline; in the rest, the populations remained very low.

The authors claim that according to these results, A. maritimus is restricted to the coasts because it depends on the salt spray originating from the sea.

I disagree. Their results don't demonstrate anything definite. If salt were the main requirement, then why did the landhopper populations decline in the enclosures that received salty water? They don't offer a good answer to that. Also, why did the landhopper populations decline after January in the enclosures that received dry salt? That too remains unanswered.

The authors acknowledge 2 problems with their study. First, soil conditions at the coast where A. maritimus is naturally present differed from those at the experimental site. So, the presence or absence of salt wasn't the only factor that may have affected the results. Second, A. maritimus was transplanted to an area where there were already terrestrial landhoppers. The design of this study totally ignores the potential interactions of the pre-existing and transplanted animals (see hypothesis #2).

Another problem, not discussed in the paper is that the 5-month period seems too short for a study like this. If the landhopper population in the experimental enclosures that received salt had increased to and stayed at levels comparable to those of the coastal populations, could they state conclusively that salt was indeed the crucial factor? They probably would, but that would be erronous. How could they know that they had established stable colonies using data from 5 months, which probably represented just one season of reproduction. An experiment like this should run for several seasons to demonstrate that stable, self-sustaining colonies can or cannot be established.

We still don't know why the coastal animals are restricted to the coasts.

There may be privacy issues about being filmed without consent if the resulting clips end up in publicly available films, commercial or otherwise. In his defense, Spence brings up the common presence of security cameras, but that isn't quite the same thing since the output of such cameras are not used to make films for distribution.

People are more scared of a center-left documentary maker with an eye [that has a video camera] than the 400 ways they are filmed every day at the school, the subway, the mall.

Would they rather be filmed by a center-right documentary maker? I am not sure what the film maker's ideology has anything to do with it.

Regardless of the legal and other issues, a video camera in one's eye socket would be a cool thing to have. I wouldn't give a good eye—even one that's quite useless without a thick corrective lens in front of it—for a camera, but if I were already blind in one eye like Spence, I would jump into the opportunity to wear a prosthetic eye with a camera. Especially, if it had high-resolution macro capability. Imagine the convenience. Look! A couple of snails mating! Let me get really close to them with my eye*.

*But since you couldn't actually see with your video eye, how would you know if the camera were aimed at the target?

05 December 2008

Readers may have noticed that I don’t display a blog roll. I used to have one. Then I started disliking some of the blogs I had been reading, while others became inactive. So rather than frequently update the list, I decided to eliminate it all together.

I do follow many blogs. Which ones do I read most often? Not necessarily the ones that update most often, although that does help. Under "Reading trends", the Google Reader gives various statistics to help one determine one's favorite blogs. But what is the best index to use for that purpose? The percentage of each blog's posts I've read over a time period is not a fair indicator because it doesn't take into account a particular blog's productivity (1 post read a month out of 1 post posted a month would be a disproportionate 100%). I've considered using the number of posts read multiplied by the total number of posts, but that would be skewed by the over-productivity of some blogs.

It seems that the simple "number of posts read" is the best index. So here are my top 12 blogs for the last 30 days. The 1st number after a blog's name is the number of posts I read, while the 2nd one is the percentage of posts I read.

04 December 2008

The American Humanist Association is running a Why believe in a god? ad campaign in the Washington, DC area. I first started seeing their ads on the sides of Metro buses a few weeks ago. Today I noticed the first one inside a Metro subway car.

Yesterday, the free daily newspaper The Washington Examiner ran a front page article about the "hundreds of complaints" concerning the ads Metro had received. One complainer wrote that Metro had "a responsibility to not offend a group of people in this country." It's interesting that religionists get offended so easily by anything and everything anti-religious, but they never care if their own religious displays may be offending others. I have seen ads for local churches in the subway cars almost every December for the last 15 years or so. Has it ever dawned on any of those complainers that those religious ads may be offensive to certain other citizens of this country?

Most religionists have almost no tolerance for criticisms of their religion and, if they had an opportunity, would gladly support the suppression of all opposing beliefs.

But why is that so? Generally speaking, one would be afraid of criticism of one's ideas or beliefs, whether they were religious or secular, only if one were unsure of them. A person will tolerate opposing ideas only if he has complete confidence in his ideas or is not afraid to abandon them when necessary. It follows that the historical and present collective efforts of all monotheistic religions to oppress and censor opposition must stem from the insecure and doubtful feelings not only the religious authorities but also their followers must have towards their own beliefs. They are afraid to lose their religious beliefs, because, many of them must know deep inside that too much rational questioning will undermine the shaky ground religions sit on. And once an avalanche starts, there is no stopping it.

What are these people, who are objecting to Metro's displays of the American Humanist Association's ads, afraid of? That they will lose their religion if they hear too many arguments contrary to their beliefs? If it is that easy for them to change their minds about their "cherished" beliefs, well, let it be so. Beliefs founded on sand are not worth clinging onto.

We are...an agent for planetary evolution or an agent for planetary destruction...Do we relate to the current environmental problems as if we are users of the earth, or do we recognize that we are the byproduct of 4.5 billion years of planetary evolution?

02 December 2008

Assisted colonization (or assisted migration) has been proposed as a potential solution for the conservation of the species threatened by global warming. The basic idea is simple: individuals of a threatened species will be collected and moved to a suitable habitat further north where they are less likely to be affected by climate change.

I have been developing the ideas expressed in my previous post into a more coherent manuscript. By coincidence, the reader Andrew Broome just recently sent a link to a relevant paper. Interestingly, the subject paper1, by Stringer & Parrish (2008), discusses a failed attempt to establish a colony of the land snail Placostylus hongii, a native of New Zealand, on an island. In this case, the snail species was not threatened by climate change, but by habitat loss and nonindigenous predators (rats, etc.). Nevertheless, the results, because they exemplify the uncertainties of colonization, assisted or natural, are quite relevant for assisted colonization research.

Eleven individuals (4 adults and 7 juveniles) of P. hongii were introduced to a limestone island, called, well, Limestone Island, near the northern tip of North Island of New Zealand in August 2002. They were monitored at uneven internals and initially appeared to have been doing well and growing. But by March 2003, all were dead. The deaths are unlikely to have been from old age, because the species’ adult lifespan is estimated to be at least 30 years. (That’s a long life for a snail.)

The authors cannot pinpoint a cause for the snails' failure to survive and establish a long-term colony on the island. Although they partly blame the drought and high temperatures experienced in the summer of 2003/2004.

This example illustrates the difficulty of successfully predicting the outcomes of assisted colonization events even in cases when the biology of the subject species had been well studied. We know very little about the biology and ecology of most other terrestrial gastropod species to be confident that transplanted species will survive without creating unintended and detrimental traumas in the receiver communities–even if assisted colonization operations were logistically and economically feasible.

A flattened invertebrate on a sidewalk is a rare item at this time of the year. So I am resorting to pictures from September and October. Once again, not everything featured here was necessarily flat as a pancake, but they were all quite dead on a sidewalk somewhere.

First, here is a dragonfly. And I wasn't even close to a body of water. How about that, folks?

The next luckless invertebrate is a cricket. An Acheta species, perhaps?

But here is a really sad sight from Istanbul, photographed last October: a squished Cantareus aspersus (the good old Helix aspersa). The poor thing was out looking for something to eat following an afternoon rain when a careless Homo sapiens stepped on it crushing its shell right against the mantle—that light colored strip of tissue, one of the defining traits of the phylum Mollusca. Sometimes these snails (and slugs) are so abundant that it's difficult to avoid them. I admit I've flattened inadvertently one or two under my shoes.

To finish this episode, we go from the gastropodical to the gastronomical with a rolled out specimen of the rare Pasta sauce. If it hadn't been for its blood-red innards splattered all over the sidewalk, it would certainly have been difficult to identify this one.